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One 48v lifepo4 pack or two 24v packs?

CV350

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Apr 27, 2021
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Hello everyone. This is my first post and after doing lots of reading here I have a question. Should I configure one 48 volt pack or two 24 volt packs for my battery bank?
My inverter is a 48v Growatt SPF5000TL HVMP and I have 16 Eve 3.2v 280ah Lifepo4 battery cells in transit.
From what I have researched:

Pros of 16S
Less wiring
One BMS
Cheaper to configure that 2 x 24
Cons of 16S
If the BMS identifies something is wrong the complete battery system shuts down (no redundancy)
Takes up a wider footprint

I am leaning to two 24 packs with two BMS as space is an issue (I can stack them on top of each other) and I like the redundancy protection.
As mentioned I am a novice on this and its my first battery build and I want to put the question out there to lean on the deep knowledge here and see whether I am on track. Thanks.
 
you won't have redundancy with 24v and 2 bms... since you have 48v inverter your 2 24v battery will be in series so if one dies you have nothing.

and 2 in series can have issues... so go 48v with a 16 cell bms
 
May I inquire about your intended application? RV, Off-grid, marine, etc.?
Sure JeepDaddy. It's an Off-grid system but the power requirement most of the time is very small with the daily usage (CCTV, alarm system. security trip lights etc) not more than 5KWH. Initially I am setting it up more like an oversize UPS and won't install panels for two or three months. The issue I want to solve at the location is that the power grid is unreliable on site and its not unusual for the grid to go down for up to four hours in the wet season. However every couple of months, and when I visit the property, I also need reserve capacity to run a small air con when AC supply is down. Cost is secondary to continuity of power. Down the track I will build a full size house on the property and add another inverter or two plus more batteries (the Growatt can parallel up to six inverters in need). At that stage I will look at the economics of going partly or fully off grid. Hope that all makes sense.
 
you won't have redundancy with 24v and 2 bms... since you have 48v inverter your 2 24v battery will be in series so if one dies you have nothing.

and 2 in series can have issues... so go 48v with a 16 cell bms
You are 100% correct GSXR1000. I hadn't really thought that thru fully.

So other than footprint there is there no other argument for two 24v 8 cell packs vs one 48v 16 cell pack?

OK so I will stay 48v 16s with a single BMS. But could I also achieve the same thing (reducing the footprint or width of the pack) by running a flexible and longer busbar between the first 8 cells and the second group of 8 cells (thereby allowing me to stack them - 8 on top of 8 but still one 48v single config)?
Or does the longer cable in the middle of the pack upset the dynamics of the system?
 
You are 100% correct GSXR1000. I hadn't really thought that thru fully.

So other than footprint there is there no other argument for two 24v 8 cell packs vs one 48v 16 cell pack?

OK so I will stay 48v 16s with a single BMS. But could I also achieve the same thing (reducing the footprint or width of the pack) by running a flexible and longer busbar between the first 8 cells and the second group of 8 cells (thereby allowing me to stack them - 8 on top of 8 but still one 48v single config)?
Or does the longer cable in the middle of the pack upset the dynamics of the system?
i would say equal is better but really won't make a difference. i would use heave duty like 2/0 cable
 
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